Seasonal and pandemic strains of flu virus differentially affect the human immune system's interferon response, according to new single cell study.

As Rivera-Cardona, et al. (2024) report, "Successful replication and transmission of influenza A viruses (IAVs) requires effective subversion of the innate immune response. We developed a new single cell method to examine the interferon (IFN) response to IAV infection at the single cell level."

The researchers found that the seasonal H3N2 and H1N1 lineages differ significantly in their ability to antagonize IFN signaling and suppress IFN induction, revealing unexpected nuances in how these lineages interact with the innate immune system. They also directly examined how the IFN antagonism potential of the viral NS segment has evolved over compared decades of circulation in humans.

Altogether, their data reveal significant differences in the capacity of the seasonal H1N1 and H3N2 lineages to antagonize the IFN response at the single cell level over decades of circulation and evolution.

Reference: Rivera-Cardona J, et al. Seasonal influenza a virus lineages exhibit divergent abilities to antagonize interferon induction and signaling. PLOS Pathogens. Dec. 12, 2024. https://doi.org/10.1371/journal.ppat.1012727